You're right, I missed the part about the Liberty by a mile, absolutely my mistake. I'd read that post before and I think my brain just skipped over it reflexively.
The bottom line is that while many *say* they haven't ever crafted one, it's entirely possible that they may have received one as a drop, which could in turn make it possible for them to receive as loot, and that would explain not remembering ever crafting it.
Many people say they got one without crafting, but not one person has ever been able to prove it conclusively. They can post photos and videos and say they've never crafted it, but unless we watch 100% of their game footage with their character, and can prove they haven't shared blueprints, that's inconclusive.
Meanwhile, we know for a fact that if you craft it once, you can receive it as a world drop. So the broader point here is that if people are wondering how to get exotics as world drops, we want to give them the info that's backed up by actual patch notes and not people's best recollections.